Biology 111 chapter 3 text

Organic Molecules

Molecules and compounds that contain both carbon and hydrogen atoms.

Vital Force Theory

A nineteenth-century belief that cells contained a vital force, dividing chemistry into organic and inorganic.

Biomolecules

The four classes of organic molecules in living organisms: carbohydrates, lipids, proteins, and nucleic acids.

Carbon Atom

An element that can form covalent bonds with various elements and can create diverse organic molecules due to its ability to share electrons.

Dehydration Synthesis

A reaction that joins subunits to form larger molecules by removing a water molecule.

Hydrolytic Reaction

A reaction that breaks down biomolecules by adding a water molecule.

Functional Group

A specific combination of bonded atoms that determines the chemical reactivity of an organic molecule.

Isomers

Organic molecules that have identical molecular formulas but different atomic arrangements.

Saturated Fatty Acids

Fatty acids that lack double bonds between carbon atoms and are saturated with hydrogen atoms.

Unsaturated Fatty Acids

Fatty acids that contain double bonds between carbon atoms, affecting their shape and functionality.

Triglycerides

Fats composed of glycerol and three fatty acids, primarily used for long-term energy storage.

Phospholipids

Lipids that consist of a glycerol backbone, two fatty acids, and a phosphate group; crucial for forming cell membranes.

Steroids

Lipids characterized by a structure of four fused carbon rings, differing mainly by functional groups attached.

Cholesterol

A steroid that stabilizes cell membranes and is a precursor for other steroids like testosterone and estrogen.

Waxes

Lipids made of long-chain fatty acids linked to alcohols; they are waterproof and prevent water loss in plants.

Monosaccharides

Single sugar molecules; the simplest form of carbohydrates.

Disaccharides

Carbohydrates formed by the joining of two monosaccharides through a dehydration reaction.

Polysaccharides

Long chains of monosaccharides, serving as energy-storage or structural molecules.